You probably haven't noticed. But were you to look carefully at a box of After Eight chocolates you might spot something missing; the royal warrant has disappeared from the packaging. And when was the last time you examined a packet of Jacob's Cream Crackers? A while ago, I'd guess, because the royal warrant was discreetly removed from that brand a couple of years ago and you may not have picked up on that either.

In August last year, Mohamed Al Fayed revealed he had burned the Harrods royal warrants, first granted to the Knightsbridge store in 1913, because he believed they were cursed, but to the 800 or so other holders the general perception of royal warrants has always been the exact opposite: that they are an honour to be sought after and held on to at all costs. So much so that some brands were still using the "By Appointment to Her Majesty Queen Elizabeth the Queen Mother" warrant for several years after her death.

There are now just three royals entitled to grant warrants – the Queen, the Duke of Edinburgh and the Prince of Wales – and to get one you have to have been supplying one of the "Big Three" for at least five years before you can be put forward for approval. Given that the royal household tends to remain loyal to its suppliers, you'd have thought that once you'd got your mitts on one, the only way you'd part with it would be under duress; Benson & Hedges had its royal warrant revoked in 1999. The official reason was "due to a lack of demand in royal households"; the unofficial one being the Queen did not want to be seen to be endorsing products that killed her subjects.

Yet After Eights and Jacob's Cream Crackers now seem happy to do the unthinkable; ditch the royal warrants. So what's going on? A spokesperson for United Biscuits, which makes Jacob's, said rather gnomically yesterday: "Jacob's design policy is to utilise the royal warrant on pack, however it may not be on all packs at any one time. Jacob's currently utilises the royal warrant for its Savoury Selection tin, which brings together eight of Jacob's favourite biscuits and crackers and celebrates over 125 years of Jacob's baking expertise."

Nestlé was similarly guarded. "Our company has been proud royal warrant holders for well over 100 years, appearing on a number of different products and still pride of place in our Croydon and York offices. We are continuing to identify how we can use the royal warrant more and give it greater prominence. After Eight is a global brand sold in more than 70 countries. In December 2009, Nestlé standardised the packaging to ensure relevance and consistency in all countries, resulting in the royal warrant being removed."

Neither statement really answers the key question, though. United Biscuits may have kept the royal warrant on its Savoury Selection tin, but that doesn't really explain why it took it off the cream crackers. It wasn't as if it was an either/or situation. Similarly, Nestlé has been flogging After Eight outside the UK for years without the royal warrant being a problem, so why has it suddenly become one now?

The answer may be found in some research commissioned by brand design agency, Coley Porter Bell. Despite the enormous success of The King's Speech – 14 Bafta nominations, queues around the block (see Pass notes, page 3) – and David Cameron's assertions that the forthcoming wedding of Prince William and Kate Middleton will kickstart the UK economy, it seems that the royal brand might not be quite as strong as it once was. In a survey of 230 adults, 42% of respondents were indifferent to royal warrants, 42% thought they were unimportant, while only 13% reckoned they made a difference.

"It's hard to say that interest in royal warrants is conclusively on the wane," said Vicky Bullen, chief executive of Coley Porter Bell, "because there is no existing data with which to make a comparison. However, consumers' apparent indifference to the royal warrants has surprised us. We can only surmise there could be a number of factors at play here: that we live in a less deferential society in which the royals enjoy less prestige and political support; that the royals have failed to manage their brand and their warrants in particular – their ubiquity may have devalued them; that modern life is now so busy that people don't notice them; and that the general quality of products is higher than in the past and the mere fact something is stocked by a leading supermarket is endorsement enough of its quality."

Not that you will find any brands openly voicing such republican sentiments, because that's not what brands do. Brands like to be fluffy and inclusive: the last thing they want to do is polarise consumers. Monarchists, republicans: they want them all. But it's hard not to suspect that for all their public utterances about respecting and valuing the warrants, Nestlé and United Biscuits' decision quietly to drop the warrant from key brands says rather more about what they really think.

They are both major multinationals, where almost nothing happens by accident. Dropping the royal warrant suggests a statement of serious intent; that they think the warrant is out-dated and old-fashioned and that their sales will increase if they dispense with it. And even if those sales are considered in a global context, it is still highly revealing that the multinationals no longer feel the warrant has sufficient impact to be worth differentiating its packaging in the UK.

It is certainly a decision that has taken the advertising industry by surprise. "I can understand a royal warrant has more value in small, high-class brands, such as bespoke shoes or equestrian goods than it does in food products," says Rory Sutherland, president of the Institute of Practitioners in Advertising. "I can equally see why you wouldn't want the association of a royal warrant if you were trying to make your product appeal to the young. But After Eight and Jacob's Cream Crackers are both very traditional brands that I would have expected to have benefited from the association. At the very least, I would have expected the warrant to remain on the grounds it wasn't doing any damage.

"A few years ago Cluedo said it was getting rid of the Reverend Green as Britain was now a secular society; that drew a predictable backlash from the Daily Mail and boosted sales no end. It's possible After Eight and Jacob's are trying something similar, but I rather doubt it as they have tried not to draw anyone's attention to their dropping the warrants. So it all seems a bit bizarre."

Unless you believe the research and the general public really don't care that much about Brand Windsor any more. Why else would two multinationals drop such a prominent association?